Liquid crystal display devices are configured by interposing a liquid crystal display element between a pair of glass substrates or the like, and the thin, lightweight, and power-efficient characteristics of these devices have made them indispensable in daily life and business, for mobile uses, in various types of monitors and televisions, and so on. In recent years, liquid crystal display devices are being employed in a broad range of applications, such as electronic books, photo frames, IAs (Industrial Appliances), PCs (Personal Computers), tablet PCs, smartphones, and the like.
As the miniaturization of liquid crystal panels in liquid crystal display devices progresses, it is desirable to use as much of the display area of the liquid crystal panel as possible and to reduce the size of a terminal portion aside from the display area of the liquid crystal panel, exterior portions that cover the liquid crystal panel, and so on (also called narrowing the frame of a liquid crystal display device hereinafter).
A liquid crystal display device generally has multiple terminal portions, and it is necessary to lead the terminal portions to an external circuit. The COG (Chip on Glass) method, the TCP (Tape Carrier Package) method, and so on are used as general methods thereof.
The stated COG method is a method for mounting (pressure-bonding) an IC (Integrated Circuit) directly to a terminal portion (gate electrode and source electrode) of a thin-film transistor (TFT) substrate as the external circuit (also called a COG driver hereinafter). An FPC (Flexible Printed Circuit) is used for inputting and outputting signals to and from the IC and so on.
The stated TCP method is a method of mounting (pressure-bonding) a package, on which an IC is mounted by forming a wiring pattern of copper foil or the like on a TCP substrate having a base film of polyimide or the like, as an external circuit on a terminal portion (gate electrode and source electrode) of a TFT substrate.
The following can be given as examples of a pressure bonding device and a pressure bonding method (mounting method) that use the stated COG method and the stated TCP method.
Patent Document 1, for example, discloses a method for mounting an external circuit by mounting the external circuit on an input/output terminal of a substrate including an amorphous semiconductor layer by thermo-compression bonding, including holding a temperature of the amorphous semiconductor layer under the crystallizing temperature thereof while the thermo-compression bonding is being carried out by supplying a cooling medium at an angle from the input/output terminal side to at least one of a surface of the substrate on which the amorphous semiconductor layer is formed and a rear surface side thereof and cooling at least an area between a portion of the substrate where the input/output terminal and the external circuit are thermo-compression bonded and the amorphous semiconductor layer or at least an area of the amorphous semiconductor layer near the input/output terminal.
Patent Document 2, for examples, discloses a thermo-compression bonding device having a support platform and a thermo-compression bonding head that compresses a terminal portion of a liquid crystal display panel placed on the support platform with a connection portion of a flexible printed substrate stacked upon the terminal portion, the thermo-compression bonding device including a cooling member, and the cooling member being configured of a heat conductor and dissipating heat from a polarizing plate laminated to a surface of the liquid crystal display panel by making contact with the polarizing plate.